West Bengal Board Class 9 Math Solution Chapter 2|Class 9 MathLaws of Indices|WBBSE Class 9 Math koshe dekhi 2|Ganit Prakash Class 9 Solution koshe dekhi 2|গণিত প্রকাশ সমাধান নবম শ্রেণী|গণিত প্রকাশ সমাধান সূচকের নিয়মাবলি ৯ কষে দেখি 2|WBBSE 9 Solution In Bengali|Ganit Prakash Solution Class 9 In Bengali.

Share this page using :

সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
কষে দেখি - 2

1. মান নির্ণয় করো :

(i) \((\sqrt[5]{8})^{\frac{5}{2}} \times(16)^{-\frac{3}{2}}\)
\((\sqrt[5]{8})^{\frac{5}{2}} \times(16)^{\frac{-3}{2}}\)
\(=\left[\left(2^{3}\right)^{\frac{1}{5}}\right]^{\frac{5}{2}} \times\left(2^{4}\right)^{\frac{-3}{2}}\)
\(=2^{\frac{3}{5}} \times \frac{5}{2} \times 2^{4} \times\left(-\frac{3}{2}\right)\)
\(=2^{\frac{3}{2}} \times 2^{-6}\)
\(=2^{\frac{3}{2}-6}\)
\(=2^{\frac{3-12}{2}}\)
\(=2^{\frac{-9}{2}}\)
(ii) \(\left\{(125)^{-2} \times(16)^{-\frac{3}{2}}\right\}^{-\frac{1}{6}}\)
\(\left\{(125)^{-2} \times(16)^{\frac{-3}{2}}\right\}^{\frac{-1}{6}}\)
\(=\left\{\left(5^{3}\right)^{-2} \times\left(2^{4}\right)^{\frac{-3}{2}}\right\}^{\frac{-1}{6}}\)
\(=\left\{5^{-6} \times 2^{-6}\right\}^{\frac{-1}{6}}\)
\(=(5 \times 2)^{(-6) \times\left(\frac{1}{-6}\right)}\)
\(=10^{1}\)
\(=10\)
সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
আজই Install করুন Chatra Mitra
(iii) \(4^{\frac{1}{3}} \times\left[2^{\frac{1}{3}} \times 3^{\frac{1}{2}}\right] \div 9^{\frac{1}{4}}\)
\(4^{\frac{1}{3}} \times\left[2^{\frac{1}{3}} \times 3^{\frac{1}{2}}\right] \div 9^{\frac{1}{4}}\)
\(=\left(2^{2}\right)^{\frac{1}{3}} \times\left[2^{\frac{1}{3}} \times 3^{\frac{1}{2}}\right] \div\left(3^{2}\right)^{\frac{1}{4}}\)
\(=2^{\frac{2}{3}} \times 2^{\frac{1}{3}} \times 3^{\frac{1}{2}} \times \frac{1}{3^{\frac{1}{2}}}\)
\(=2^{\frac{2}{3}+\frac{1}{3}}\)
\(=2^{\frac{2+1}{3}}\)
\(=2^{\frac{3}{3}}\)
\(=2^{1}\)
\(=2\)

2. সরল করো :

(i) \(\left(8 a^{3} \div 27 x^{-3}\right)^{\frac{2}{3}} \times\left(64 a^{3} \div 27 x^{-3}\right)^{-\frac{2}{3}}\)
\(\left(8 a^{3} \div 27 x^{-3}\right)^{\frac{2}{3}} \times\left(64 a^{3} \div 27 x^{-3}\right)^{\frac{-2}{3}}\)
\(=\left[(2 \mathrm{a})^{3} \div\left(\frac{3}{x}\right)^{3}\right]^{\frac{2}{3}} \times\left[(4 \mathrm{a})^{3} \div\left(\frac{3}{x}\right)^{3}\right]^{-\frac{2}{3}}\)
\(=\left[(2 a)^{3} \times\left(\frac{x}{3}\right)^{3}\right]^{\frac{2}{3}} \times\left[(4 a)^{3} \times\left(\frac{x}{3}\right)^{3}\right]^{-\frac{2}{3}}\)
\(=\left[\left(2 a \times \frac{x}{3}\right)^{3}\right]^{\frac{2}{3}} \times\left[\left(4 a \times \frac{x}{3}\right)^{3}\right]^{-\frac{2}{3}}\)
\( =\left(\frac{2 a x}{3}\right)^{2} \times\left(\frac{4 a x}{3}\right)^{-2}\)
\(=\left(\frac{2 a x}{3}\right)^{2} \times\left(\frac{3}{4 a x}\right)^{2} \)
\(=\left(\frac{2 a x}{3} \times \frac{3}{4 a x}\right)^{2}\)
\(=\left(\frac{1}{2}\right)^{2}\)
\(=\frac{1}{4}\)
সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
আজই Install করুন Chatra Mitra
(ii) \(\left\{\left(x^{-5}\right)^{\frac{2}{3}}\right\}^{-\frac{3}{10}}\)
\(\left\{\left(x^{-5}\right)^{\frac{2}{3}}\right\}^{\frac{-3}{10}}\)
\(=\left\{x^{\frac{-10}{3}}\right\}^{-\frac{3}{10}}\quad\left[\because\left(a^{m}\right)^{n}=a^{m n}\right]\)
\(=x^{1}\)
\(=x\)
(iii) \(\left[\left\{\left(2^{-1}\right)^{-1}\right\}^{-1}\right]^{-1}\)
\(\left[\left\{\left(2^{-1}\right)^{-1}\right\}^{-1}\right]^{-1}\)
\(=\left[\left\{2^{-1}\right\}^{-1}\right]^{1}\)
\(=\left[2^{-1}\right]^{-1}\)
\(=2^{1}\)
\(=2\)
(iv) \(\sqrt[3]{a^{-2}} \cdot b \times \sqrt[3]{b^{-2}} \cdot c \times \sqrt[3]{c^{-2}} \cdot a\)
\(\sqrt[3]{a^{-2}} \cdot b \times \sqrt[3]{b^{-2}} \cdot c \times \sqrt[3]{c^{-2}} \cdot a\)
\( =a^{-\frac{2}{3}} \cdot b \times b^{-\frac{2}{3}} \cdot c \times c^{-\frac{2}{3}} \cdot a \)
\(=a^{1-\frac{2}{3}} \times b^{1-\frac{2}{3}} \times c^{1-\frac{2}{3}}\)
\(=a^{\frac{1}{3}} b^{\frac{1}{3}} c^{\frac{1}{3}} \)
\(=(a b c)^{\frac{1}{3}}\)
\(=\sqrt[3]{a b c} \)
(v) \(\left(\frac{4^{m+\frac{1}{4}} \times \sqrt{2.2^{m}}}{2 . \sqrt{2^{-m}}}\right)^{\frac{1}{m}}\)
\(\left(\frac{4^{m+\frac{1}{4}} \times \sqrt{2.2^{m}}}{2 . \sqrt{2^{-m}}}\right)^{\frac{1}{m}}\)
\(=\left[\frac{\left(2^{2}\right)^{m+\frac{1}{4}} \times \sqrt{2^{1+m}}}{2 \cdot 2^{-\frac{m}{2}}}\right]^{\frac{1}{m}} \)
\(=\left[\frac{2^{2 m+\frac{1}{2}} \times 2^{\frac{1+m}{2}}}{2^{1-\frac{m}{2}}}\right]^{\frac{1}{m}}\)
\(=\left[\frac{2^{2 m+\frac{1}{2}+\frac{1+m}{2}}}{2^{1-\frac{m}{2}}}\right]^{\frac{1}{m}} \)
\(=\left[2^{2 m+\frac{1}{2}+\frac{1}{2}+\frac{m}{2}-1+\frac{m}{2}}\right]^{\frac{1}{m}} \)
\(=\left[2^{2 m+\frac{m}{2}+\frac{m}{2}+\frac{1}{2}+\frac{1}{2}-1}\right]^{\frac{1}{m}}\)
\(=\left[2^{3 m+1-1}\right]^{\frac{1}{m}}\)
\(=\left(2^{3 m}\right)^{\frac{1}{m}}\)
\(=2^{3}\)
\(=8\)
(vi) \(9^{-3} \times \frac{16^{\frac{1}{4}}}{6^{-2}} \times\left(\frac{1}{27}\right)^{-\frac{4}{3}}\)
\(9^{-3} \times \frac{16^{\frac{1}{4}}}{6^{-2}} \times\left(\frac{1}{27}\right)^{-\frac{4}{3}}\)
\( =\left(3^{2}\right)^{-3} \times \frac{\left(2 \right)^{\frac{1}{4}}}{(3.2)^{-2}} \times\left(\frac{1}{3}\right)^{3 \times\left(-\frac{4}{3}\right)}\)
\(=3^{-6} \times \frac{2}{3^{-2} \times 2^{-2}} \times\left(\frac{1}{3}\right)^{-4}\)
\(=3^{-6+2+4} \times 2^{1+2}\)
\(=3^{0} \times 2^{3}\)
\(=8\quad\left[\because 3^{0}=1\right] \)
(vii) \(\left(\frac{x^{a}}{x^{b}}\right)^{a^{2}+a b+b^{2}}\times\left(\frac{x^{b}}{x^{c}}\right)^{b^{2}+b c+c^{2}} \times\left(\frac{x^{c}}{x^{a}}\right)^{c^{2}+c a+a^{2}}\)
\(\left(\frac{x^{a}}{x^{b}}\right)^{a^{2}+a b+b^{2}}\times\left(\frac{x^{b}}{x^{c}}\right)^{b^{2}+b c+c^{2}} \times\left(\frac{x^{c}}{x^{a}}\right)^{c^{2}+c a+a^{2}}\)
\(=x^{(a-b)}\left(a^{2}+a b+b^{2}\right) \times x^{(b-c)}\left(b^{2}+b c+c^{2}\right)\times x^{(c-a)\left(c^{2}+c a+a^{2}\right)}\)
\( =x^{a^{3}-b^{3}} \times x^{b^{3}-c^{3} }\times x^{c^{3}-a^{3}} \)
\(=x^{a^{3}-b^{3}+b^{3}-c^{3}+c^{3}-a^{3}}\)
\(=x^{0}\)
\(=1 \)

3. মানের উর্ধ্বক্রমানুসারে সাজাও :

(i) \(5^{\frac{1}{2}}, 10^{\frac{1}{4}}, 6^{\frac{1}{3}}\)
\(5^{\frac{1}{2}}, 10^{\frac{1}{4}}, 6^{\frac{1}{3}}\)
\(\because 2,4,3\)-এর ল.সা.গু \(12\)
\( 5^{\frac{1}{2}}=5^{\frac{6}{12}}=\sqrt[12]{5^{6}}=\sqrt[12]{15625} \)
\(10^{\frac{1}{4}}=10^{\frac{3}{12}}=\sqrt[12]{10^{3}}=\sqrt[12]{1000} \)
\(6^{\frac{1}{3}}=6^{\frac{4}{12}}=\sqrt[12]{6^{4}}=\sqrt[12]{1296} \)
\(\because \) \(1000 < 1296 < 15625 \)
\(\therefore\) \(\sqrt[12]{1000} < \sqrt[12]{1296} < \sqrt[12]{15625} \)
\(\therefore\) \(5^{\frac{1}{2}} > 6^{\frac{1}{3}} > 10^{\frac{1}{4}} \)
(ii) \(3^{\frac{1}{3}}, 2^{\frac{1}{2}}, 8^{\frac{1}{4}}\)
\(3^{\frac{1}{3}}, 2^{\frac{1}{2}}, 8^{\frac{1}{4}}\)
\(\because 2,4,3\)-এর ল.সা.গু \(12\)
\( 3^{\frac{1}{3}}=3^{\frac{4}{12}}=\sqrt[12]{3^{4}}=\sqrt[12]{81}\)
\(2^{\frac{1}{2}}=2^{\frac{6}{12}}=\sqrt[12]{2^{6}}=\sqrt[12]{64} \)
\(8^{\frac{1}{4}}=8^{\frac{3}{12}}=\sqrt[12]{8^{3}}=\sqrt[12]{512} \)
\(\because \) \(64 < 81 < 512 \)
\(\therefore\) \(\sqrt[12]{64} < \sqrt[12]{81} < \sqrt[12]{512} \)
\(\therefore\) \(2^{\frac{1}{2}} < 3^{\frac{1}{3}} < 8^{\frac{1}{4}} \)
(iii) \(2^{60}, 3^{48}, 4^{36}, 5^{24}\)
\(2^{60}, 3^{48}, 4^{36}, 5^{24} \)
\(2^{60}=\left(2^{5}\right)^{12}=(32)^{12} \)
\(3^{48}=\left(3^{4}\right)^{12}=(81)^{12} \)
\(4^{36}=\left(4^{3}\right)^{12}=(64)^{12} \)
\(5^{24}=\left(5^{2}\right)^{12}=(25)^{12} \)
\(\because \) \(25 < 32 < 64 < 81 \)
\(\therefore\) \((25)^{12} < (32)^{12} < (64)^{12} < (81)^{12}\)
\(\therefore\) \(5^{24} < 2^{60} < 4^{36} < 3^{48} \)

4. প্রমাণ করো :

(i) \(\left(\frac{a^{q}}{a^{r}}\right)^{p} \times\left(\frac{a^{r}}{a^{p}}\right)^{q} \times\left(\frac{a^{p}}{a^{q}}\right)^{r}=1\)
বামপক্ষ, \(\left(\frac{a^{q}}{a^{r}}\right)^{p} \times\left(\frac{a^{r}}{a^{p}}\right)^{q} \times\left(\frac{a^{p}}{a^{q}}\right)^{r}\)
\(=a^{(q-r) p} \times a^{(r-p) q} \times a^{(p-q) r}\)
\(=a^{p q-p r+q r-p q+p r-q r}\)
\(=a^{0}=1=\) ডানপক্ষ (প্রমাণিত)
(ii) \(\left(\frac{x^{m}}{x^{n}}\right)^{m+n} \times\left(\frac{x^{n}}{x^{\ell}}\right)^{n+\ell} \times\left(\frac{x^{\ell}}{x^{m}}\right)^{\ell+m}\)
বামপক্ষ, \(\left(\frac{x^{\mathrm{m}}}{x^{\mathrm{n}}}\right)^{\mathrm{m}+\mathrm{n}}\left(\frac{x^{\mathrm{n}}}{x^{l}}\right)^{\mathrm{n}+l}\left(\frac{x^{l}}{x^{\mathrm{m}}}\right)^{l+\mathrm{m}}\)
\(=x^{(\mathrm{m}-\mathrm{n})(\mathrm{m}+\mathrm{n})} \times x^{(\mathrm{n}-l)(\mathrm{n}+l)} \times x^{(l-\mathrm{m})(l+\mathrm{m})}\)
\(=x^{m^{2}-n^{2}} \times x^{n^{2}-l^{2}} \times l^{2}-m^{2}\)
\(=x^{\mathrm{m}^{2}-\mathrm{n}^{2}+\mathrm{n}^{2}-l^{2}+l^{2}-\mathrm{m}^{2}}\)
\(=x^{0}=1=\) ডানপক্ষ (প্রমাণিত)
(iii) \(\left(\frac{x^{m}}{x^{n}}\right)^{m+n-\ell} \times\left(\frac{x^{n}}{x^{\ell}}\right)^{n+\ell-m} \times\left(\frac{x^{\ell}}{x^{m}}\right)^{\ell+m-n}=1\)
বামপক্ষ, \(\left(\frac{x^{\mathrm{m}}}{x^{\mathrm{n}}}\right)^{\mathrm{m}+\mathrm{n}-l} \times\left(\frac{x^{\mathrm{n}}}{x^{l}}\right)^{\mathrm{n}+l-\mathrm{m}} \times\left(\frac{x^{l}}{x^{\mathrm{m}}}\right)^{l+\mathrm{m}-\mathrm{n}}\)
\( =\left(x^{\mathrm{m}-\mathrm{n}}\right)^{\mathrm{m}+\mathrm{n}-l} \times\left(x^{\mathrm{n}-l}\right)^{\mathrm{n}+l-\mathrm{m}} \times\left(x^{l-\mathrm{m}}\right)^{l+\mathrm{m}-\mathrm{n}} \)
\( =x^{(\mathrm{m}-\mathrm{n})(\mathrm{m}+\mathrm{n})-l(\mathrm{m}-\mathrm{n})} \times x^{(\mathrm{n}-l)(\mathrm{n}+l)-\mathrm{m}(\mathrm{n}-l)} \times x^{(l-\mathrm{m})(l+\mathrm{m})-\mathrm{n}(l-\mathrm{m})} \)
\( = x^{m^{2}-n^{2}-l m+l n} \times x^{n^{2}-l^{2}-m n}+\mathrm{ml} \times x^{l^{2}}-\mathrm{m}^{2}-\mathrm{nl} +\mathrm{mn} \)
\(=x^{m^{2}-n^{2}-l m+ln+n^{2}-l^{2}-m n+m l+l^{2}-m l^{2}-n l+m n}\)
\(=x^{0}=1=\) ডানপক্ষ (প্রমাণিত)
(iv) \(\left(a^{\frac{1}{x-y}}\right)^{\frac{1}{x-z}}\)\( \times\left(a^{\frac{1}{y-z}}\right)^{\frac{1}{y-x}}\)\( \times\left(a^{\frac{1}{z-x}}\right)^{\frac{1}{z-y}}=1\)
বামপক্ষ, \(\left(a^{\frac{1}{x-y}}\right)^{\frac{1}{x-z}} \times\left(a^{\frac{1}{y-z}}\right)^{\frac{1}{y-x}} \times\left(a^{\frac{1}{z-x}}\right)^{\frac{1}{z-y}}\)
\( =a^{\frac{1}{(x-y)(x-z)}} \times a^{\frac{1}{(y-z)(y-x)}} \times a^{\frac{1}{(z-x)(z-y)}} \)
\(=a^{\frac{1}{(x-y)(x-z)}+\frac{1}{(y-z)(y-x)}+\frac{1}{(z-x)(z-y)}} \)
\(=a^{\frac{-1}{(x-y)(z-x)}+\frac{-1}{(y-z)(x-y)}+\frac{1}{(z-x)(y-z)}} \)
\( =a^{-\left[\frac{1}{(x-y)(z-x)}+\frac{1}{(y-z)(x-y)}+\frac{1}{(z-x)(y-z)}\right]} \)
\(=a^{-\left[\frac{y-z+z-x+x-y}{(x-y)(y-z)(z-x)}\right]}\)
\(=a^{-\frac{0}{(x-y)(y-z)(z-x)}} \)
\(=a^{0}=1=\) ডানপক্ষ (প্রমাণিত)
সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
আজই Install করুন Chatra Mitra
5. \(x+z=2 y\) এবং \(b^{2}=a c\) হলে, দেখাই যে, \(a^{y-z} b^{z-x} c^{x-y}=1\)
প্রদত্ত, \(x+z=2 y\)
বা, \(x-y=y-z\)
বামপক্ষ, \(a^{y-z} \cdot b^{z-x} \cdot c^{x-y}\)
\( =a^{x-y} \cdot c^{x-y} \cdot b^{z-x}\quad[\because x-y=y-z] \)
\(=(a c)^{x-y} \cdot b^{z-x} \)
\(=\left(b^{2}\right)^{x-y} \cdot b^{z-x} \quad\left[\because b^{2}=a c\right] \)
\(=b^{2 x-2 y+z-x}\)
\(=b^{x+z-2 y} \)
\(=b^{2 y-2 y}\quad[\because x+z=2 y] \)
\(=b^{0}=1=\) ডানপক্ষ (প্রমাণিত)
6. \(a=x y^{p-1}, b=x y^{q-1},\) এবং \( c=x y^{r-1}\) হলে, দেখাও যে, \(a^{q-r} b^{r-p} c^{p-q}=1\)
বামপক্ষ, \(a^{q-r} b^{r-p} c^{p-q}\)
\(=\left(x y^{p-1}\right)^{q-r}\left(x y^{q-1}\right)^{r-p}\left(x y^{r-1}\right)^{p-q}\quad{\left[\because a=x y^{p-1} b=x y^{q-1} c=x y^{r-1}\right]}\)
\(=x^{q-r} y^{(p-1)(q-r)} \cdot x^{r-p} y^{(q-1)(r-p)}.x^{p-q} y^{(r-1)(p-q)}\)
\(=x^{q-r+r-p+p-q} y^{(p-1)(q-r)+(q-1)(r-p)+(r-1)(p-q)}\)
\(=x^{0} \cdot y ^{p q-p r-q+r+q r-p q-r+p+p r-q r-p +q }\)
\(=1 \cdot y^{0}=1 \cdot 1=1=\) ডানপক্ষ (প্রমাণিত)
7. \(x^{\frac{1}{a}}=y^{\frac{1}{b}}=z^{\frac{1}{c}}\) এবং \(x y z=1\) হলে, দেখাই যে, \(a+b+c=0\)
\(x^{\frac{1}{a}}=y^{\frac{1}{b}}=z^{\frac{1}{c}}=K\) (ধরি) \(\quad[\mathrm{K} \neq 0]\)
\(\therefore x^{\frac{1}{a}}=\mathrm{K}, y^{\frac{1}{b}}=\mathrm{K},\) এবং \(z^{\frac{1}{c}}=K\)
\(\therefore x=\mathrm{K}^{\mathrm{a}},\)
\( \therefore \mathrm{y}=\mathrm{K}^{\mathrm{b}}, \)
\(\therefore \mathrm{z}=\mathrm{K}^{\mathrm{c}}\)
প্রদত্ত, \(xyz=1\)
বা, \(\mathrm{K}^{a} \cdot \mathrm{K}^{b} \cdot \mathrm{K}^{c}=K^{0}\)
বা, \(\mathrm{K}^{\mathrm{a}+\mathrm{b}+\mathrm{c}}=\mathrm{K}^{0}\)
\(\therefore a+b+c=0\) (প্রমাণিত)
8. \(a^{x}=b^{y}=c^{z}\) এবং \(a b c=1\) হলে, দেখাই যে, \(x y+y z+z x=0\)
\(a^{x}=b^{y}=c^{z}=K\) (ধরি) \(\quad[\mathrm{K} \neq 0]\)
বা, \(a=K^{\frac{1}{x}}, b=K^{\frac{1}{y}}\) এবং \(c=K^{\frac{1}{z}}\)
প্রদত্ত, \(a b c=1\)
বা, \(K^{\frac{1}{x}} \cdot K^{\frac{1}{y}} \cdot K^{\frac{1}{z}}=1\)
বা, \(K^{\frac{1}{x}+\frac{1}{y}+\frac{1}{z}}=K^{0}\)
বা, \(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}=0\)
বা, \(\frac{y z+x z+x y}{x y z}=0\)
বা, \(x y+y z+z x=0\) (প্রমাণিত)

9. সমাধান করো :

(i) \(49^{x}=7^{3}\)
\(49^{x}=7^{3}\)
বা, \(\left(7^{2}\right)^{x}=7^{3}\)
বা, \(7^{2 x}=7^{3} \)
\(\therefore 2 x=3\)
বা, \(x=\frac{3}{2}=1 \frac{1}{2} \)
\(\therefore\) নির্ণেয় সমাধান, \(x=1 \frac{1}{2}\)
(ii) \(2^{x+2}+2^{x-1}=9\)
\( 2^{x+2}+2^{x-1}=9 \)
বা, \(2^{x} \cdot 2^{2}+2^{x} \cdot 2^{-1}=9\)
বা, \(4 \cdot 2^{x}+\frac{2^{x}}{2}=9 \)
বা, \(2^{x} \cdot\left(4+\frac{1}{2}\right)=9 \)
বা, \(2^{x} \cdot \frac{9}{2}=9\)
বা, \(2^{x}=9 \times \frac{2}{9}\)
বা, \(2^{x}=2^{1} \)
বা, \(x=1 \)
\(\therefore\) নির্ণেয় সমাধান \(x=1\)
সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
আজই Install করুন Chatra Mitra
(iii) \(2^{x+1}+2^{x+2}=48\)
\( 2^{x+1}+2^{x+2}=48 \)
বা, \(2^{x} \cdot 2^{1}+2^{x} \cdot 2^{2}=48 \)
বা, \(2^{x}(2+4)=48 \)
বা, \(2^{x} \cdot 6=48\)
বা, \(2^{x}=\frac{48 }{6}\)
বা, \(2^{x}=2^{3}\)
বা, \(x=3\)
\(\therefore\) নির্ণেয় সমাধান \(x=3\)
(iv) \(2^{4x } . 4^{3 x-1}=\frac{4^{2 x}}{2^{3 x}}\)
\( 2^{4 x} \cdot 4^{3 x-1}=\frac{4^{2 x}}{2^{3 x}}\)
বা, \(2^{4 x} \cdot\left(2^{2}\right)^{3 x-1}=\frac{\left(2^{2}\right)^{2 x}}{2^{3 x}} \)
বা, \(2^{4 x} \cdot 2^{6 x-2}=2^{4 x-3 x} \)
বা, \(2^{4 x+6 x-2}=2^{4 x-3 x}\)
বা, \(2^{10 x-2}=2^{x} \)
\(\therefore\) \(10 x-2=x \)
বা, \(10 x-x=2 \)
বা, \(9 x=2\)
বা, \(x=\frac{2}{9} \)
\(\therefore\) নির্ণেয় সমাধান \(x=\frac{2}{9} \)
(v) \(9+81^{x}=27^{2-x}\)
\(9 \times 81^{x}=27^{2-x}\)
বা, \(3^{2} \times\left(3^{4}\right)^{x}=\left(3^{3}\right)^{2-x} \)
বা, \(3^{2} \times 3^{4 x}=3^{6-3 x} \)
বা, \(3^{2+4 x}=3^{6-3 x}\)
\(\therefore\) \(2+4 x=6-3 x\)
বা, \(4 x+3 x=6-2\)
বা, \(7 x=4\)
\(\therefore\) \(x=\frac{4}{7} \)
\(\therefore\) নির্ণেয় সমাধান \(x=\frac{4}{7} \)
(vi) \(2^{5 x+4}+2^{9}=2^{10}\)
\(2^{5 x+4}+2^{9}=2^{10}\)
বা, \(2^{5 x+4}=2^{10}-2^{9}\)
বা, \(2^{5 x+4}=2^{9} \cdot(2-1)\)
বা, \(2^{5 x+4}=2^{9}\)
\(\therefore\) \(5 x+4=9\)
বা, \(5 x=9-4 \)
বা, \(5 x=5\)
বা, \(x=1 \)
\(\therefore\) নির্ণেয় সমাধান \(x=1 \)
(vii) \(6^{2 x+4}=3^{3 x} . 2^{x+8}\)
\( 6^{2 x+4}=3^{3 x} \cdot 2^{x+8}\)
বা, \((2 \cdot 3)^{2 x+4}=3^{3 x} \cdot 2^{x+8}\)
বা, \(2^{2 x+4} \times 3^{2 x+4}=3^{3 x} \times 2^{x+8}\)
বা, \(\frac{2^{2 x+4}}{2^{x+8}}=\frac{3^{3 x}}{3^{2 x+4}}\)
বা, \(2^{2 x+4-x-8}=3^{3 x-2 x-4}\)
বা, \(2^{x-4}=3^{x-4}\)
বা, \(\left(\frac{2}{3}\right)^{x-4}=1\)
বা, \(\left(\frac{2}{3}\right)^{x-4}=\left(\frac{2}{3}\right)^{0}\)
\(\therefore\) \(x-4=0\)
\(\therefore\) \(x=4 \)
\(\therefore\) নির্ণেয় সমাধান \(x=4 \)

10. বহু বিকল্পীয় প্রশ্ন (M.C.Q) :

(i) \((0.243)^{0.2} \times(10)^{0.6}\)-এর মান
(a) 0.3 (b) 3 (c) 0.9 (d) 9
\((0.243)^{0.2} \times(10)^{0.6}\)
\(=\left(\frac{243}{1000}\right)^{\frac{2}{10}} \times(10)^{\frac{6}{10}}\)
\(=\left(\frac{3^{5}}{10^{3}}\right)^{\frac{1}{5}} \times(10)^{\frac{3}{5}}\)
\(=\frac{3^{5 \times \frac{1}{5}}}{10^{3 \times \frac{1}{5}}} \times 10^{\frac{3}{5}}\)
\(=\frac{3}{10^{\frac{3}{5}}} \times 10^{\frac{3}{5}}\)
\(=3\)
(ii) \(2^{\frac{1}{2}} \times 2^{-\frac{1}{2}} \times(16)^{\frac{1}{2}}\) -এর মান
(a) 1 (b) 2 (c) 4 (d) \(\frac{1}{2}\)
\(2^{\frac{1}{2}} \times 2^{-\frac{1}{2}} \times(16)^{\frac{1}{2}}\)
\( =2^{\frac{1}{2}} \times 2^{-\frac{1}{2}} \times 16^{\frac{1}{2}}\)
\(=2^{\frac{1}{2}+\left(-\frac{1}{2}\right)} \times\left(4^{2}\right)^{\frac{1}{2}}\)
\(=2^{0} \times 4\)
\(=1 \times 4\)
\(=4 \)
(iii) \(4^{x}=8^{3}\) হলে \(x\)-এর মান
(a) \(\frac{3}{2}\) (b) \(\frac{9}{2}\) (c) 3 (d) 9
\(4^{x}=8^{3}\)
বা, \(\left(2^{2}\right)^{x}=\left(2^{3}\right)^{3}\)
বা, \( 2^{2 x}=2^{9} \)
বা, \(2 x=9\)
\(\therefore\) \(x=\frac{9}{2} \)
(iv) \(20^{-x}=\frac{1}{7}\) হলে, \((20)^{2 x}\)-এর মান
(a) \(\frac{1}{49}\) (b) 7 (c) 49 (d) 1
\(20^{-x}=\frac{1}{7}\)
বা, \(\left(20^{-x}\right)^{-2}=\left(\frac{1}{7}\right)^{-2}\)
বা, \(20^{2 x}=7^{2}\)
\(\therefore 20^{2 x}=49\)
(v) \(4 \times 5^{x}=500\) হলে, \(\mathbf{x}^{\mathbf{x}}\)-এর মান কত?
(a) 8 (b) 1 (c) 64 (d) 27
\(4 \times 5^{x}=500\)
বা, \( 5^{x}=\frac{500 }{4}\)
বা, \(5^{x}=125\)
বা, \(5^{x}=5^{3}\)
\(\therefore\) \(x=3\)
\(\therefore\) \(x^{x}=3^{3}=27 \)

11. সংক্ষিপ্ত উত্তরভিত্তিক প্রশ্ন :

(i) \((27^{x})=(81^{y})\) হলে, \(x : y\) কত হয় লিখি ?
\((27^{x})=(81^{y})\)
বা, \(\left(3^{3}\right)^{x}=\left(3^{4}\right)^{y}\)
বা, \(3^{3 x}=3^{4 y}\)
\(\therefore 3 x=4 y\)
বা, \(\frac{x}{y}=\frac{4}{3} \)
বা, \(x: y=4: 3\)
(ii) \(\left(5^{5}+0.01\right)^{2}-\left(5^{5}-0.01\right)^{2}=5^{x}\) হলে, \(x\)-এর মান কত?
\(\left(5^{5}+0.01\right)^{2}-\left(5^{5}-0.01\right)^{2}=5^{x}\)
বা, \( 4 \times 5^{5} \times 0.01=5^{x}\quad\left[\because(a+b)^{2}-(a-b)^{2}=4 a b\right]\)
বা, \(4 \times 5^{5} \times \frac{1}{100 }=5^{x}\)
বা, \(\frac{5^{5}}{5^{2}}=5^{x} \)
বা, \(5^{5-2}=5^{x}\)
বা, \( 5^{3}=5^{x} \)
\(\therefore\) \(x=3 \)
(iii) \(3 \times 27^{x}=9^{x+4}\) হলে, \(x\)-এর মান কত হিসাব করে লিখি।
\( 3 \times 27^{x}=9^{x+4} \)
বা, \(3 \times\left(3^{3}\right)^{x}=\left(3^{2}\right)^{x+4} \)
বা, \(3 \times 3^{3 x}=3^{2 x+8}\)
বা, \(3^{1+3 x}=3^{2 x+8}\)
\(\therefore\) \(1+3 x=2 x+8\)
বা, \(3 x-2 x=8-1 \)
\(\therefore\) \(x=7 \)
(iv) \(\sqrt[3]{\left(\frac{1}{64}\right)^{\frac{1}{2}}}\) এর মান কত হিসাব করে লিখি।
\( \sqrt[3]{\left(\frac{1}{64}\right)^{\frac{1}{2}}}\)
\(=\sqrt[3]{\left(\frac{1}{64}\right)^{\frac{1}{2}}}\)
\(=\sqrt[3]{\left(\frac{1}{8}\right)^{2 \times \frac{1}{2}}}\)
\(=\sqrt[3]{\left(\frac{1}{8}\right)}\)
\(=\sqrt[3]{\left(\frac{1}{2}\right)^{3}}\)
\(=\sqrt[3]{2^{-3}}\)
\(=2^{-3 \times \frac{1}{3}}\)
\(=2^{-1}\)
\(=\frac{1}{2} \)
(v) \(3^{3^{3}}\) এবং \(\left(3^{3}\right)^{3}\)-এর মধ্যে কোনটি বৃহত্তর যুক্তিসহ লিখি।
\( 3^{3^{3}}=3^{27}\)
\(\left(3^{3}\right)^{3}=3^{9}\)
\(\because \) \(27 > 9\)
\(\therefore\) \(3^{27} > 3^{9} \)
অর্থাৎ, \(3^{3^{3}} > \left(3^{3}\right)^{3} \)
সূচকের নিয়মাবলি|Laws of Indices|West Bengal Board Class 9 Math|Class 9 Chapter 2|নবম শ্রেণী|Chapter 2|Ganit Prakash Class 9 Solution
আজই Install করুন Chatra Mitra
এই Page টি বা এই Website টির কোন প্রকার বিষয়বস্তু কপি করা বা সম্পাদনা করা নিষিদ্ধ। ভারতীয় Copywright আইন 1957 এর ধারা 63 অনুযায়ী, এই ফাইলটির সমস্ত অধিকার 'ছাত্র মিত্র Mathematics' অ্যাপ দ্বারা সংরক্ষিত। ছাত্র মিত্রের অনুমতি ছাড়া, এই Page টি বা এই Website টির কোন প্রকার বিষয়বস্তু কপি করা বা সম্পাদনা করা আইনত দন্ডনীয় অপরাধ। কেউ ছাত্র মিত্রের অনুমতি ছাড়া, এই Page টি বা এই Website টির কোন প্রকার বিষয়বস্তু কপি বা সম্পাদনা করলে ছাত্র মিত্র কতৃপক্ষ তার বিরুদ্ধে সকল প্রকার কঠোর আইনি পদক্ষেপ করবে।

Leave a Comment

Your email address will not be published. Required fields are marked *

Share this page using:

Exit mobile version